In recent years toners have been desired to have smaller particle sizes from the viewpoint of achieving even higher image qualities. Processes for preparing toners include a melt-kneading and pulverization method, and a wet process such as an emulsification and aggregation method. When a toner containing a resin binder containing a crystalline polyester as a main component is prepared by the melt-kneading and pulverization method, it is difficult to control the pulverization, thereby making it impractical.
JP2003-122051 A and JP2001-305796 A each discloses an invention relating to the preparation of a toner by an emulsification and aggregation method, which is a wet process. However, in the process described in JP2003-122051 A, a resin is limited to one that is soluble in an organic solvent, and in the case of a resin having low solubility in an organic solvent, the yield of the toner is dramatically lowered. In addition, in the process described in JP2001-305796 A, a resin is limited to crystalline polyester containing specified raw material monomers.